An algorithm to identify antidepressant users with a diagnosis of depression from prescription data

The mental health of all children in contact with social services: a population-wide record-linkage study in Northern Ireland

AIMS

Children in contact with social services are at high risk for mental ill health, but it is not known what proportion of the child population has contact with social services or how risk varies within this group compared to unexposed peers. We aim to quantify the extent and nature of contact with social services within the child population in Northern Ireland (NI) and the association with mental ill health. We also examine which social care experiences identify those most at risk.

METHODS

This is a population-based record-linkage study of 497,269 children (aged under 18 years) alive and resident in NI in 2015 using routinely collected health and social care data. Exposure was categorized as (1) no contact, (2) referred but assessed as not in need (NIN), (3) child in need (CIN) and (4) child in care (CIC). Multilevel logistic regression analyses estimated odds ratios (ORs) for mental ill health indicated by receipt of psychotropic medication (antidepressants, anxiolytics, antipsychotics and hypnotics), psychiatric hospital admission and hospital-presenting self-harm or ideation.

RESULTS

Over one in six children (17.2%, n = 85,792) were currently or previously in contact with social services, and almost one child in every 20 (4.8%, n = 23,975) had contact in 2015. Likelihood of any mental ill health outcome increased incrementally with the level of contact with social services relative to unexposed peers: NIN (OR 5.90 [95% confidence interval (CI) 5.10-6.83]), CIN (OR 5.99 [95% CI 5.50-6.53]) and CIC (OR 12.60 [95% CI 10.63-14.95]). All tiers of contact, number of referrals, number of care episodes and placement type were strongly associated with the likelihood of mental ill health.

CONCLUSION

Children who have contact with social services account for a large and disproportionate amount of mental ill health in the child population. Likelihood of poor mental health across indicators is highest in care experienced children but also extends to the much larger population of children in contact with social services but never in care. Findings suggest a need for targeted mental health screening and enhanced support for all children in contact with social services.

Exploring different research questions via complex multi-state models when using registry-based repeated prescriptions of antidepressants in women with breast cancer and a matched population comparison group

BACKGROUND

Multi-state models are used to study several clinically meaningful research questions. Depending on the research question of interest and the information contained in the data, different multi-state structures and modelling choices can be applied. We aim to explore different research questions using a series of multi-state models of increasing complexity when studying repeated prescriptions data, while also evaluating different modelling choices.

METHODS

We develop a series of research questions regarding the probability of being under antidepressant medication across time using multi-state models, among Swedish women diagnosed with breast cancer (n = 18,313) and an age-matched population comparison group of cancer-free women (n = 92,454) using a register-based database (Breast Cancer Data Base Sweden 2.0). Research questions were formulated ranging from simple to more composite ones. Depending on the research question, multi-state models were built with structures ranging from simpler ones, like single-event survival analysis and competing risks, up to complex bidirectional and recurrent multi-state structures that take into account the recurring start and stop of medication. We also investigate modelling choices, such as choosing a time-scale for the transition rates and borrowing information across transitions.

RESULTS

Each structure has its own utility and answers a specific research question. However, the more complex structures (bidirectional, recurrent) enable accounting for the intermittent nature of prescribed medication data. These structures deliver estimates of the probability of being under medication and total time spent under medication over the follow-up period. Sensitivity analyses over different definitions of the medication cycle and different choices of timescale when modelling the transition intensity rates show that the estimates of total probabilities of being in a medication cycle over follow-up derived from the complex structures are quite stable.

CONCLUSIONS

Each research question requires the definition of an appropriate multi-state structure, with more composite ones requiring such an increase in the complexity of the multi-state structure. When a research question is related with an outcome of interest that repeatedly changes over time, such as the medication status based on prescribed medication, the use of novel multi-state models of adequate complexity coupled with sensible modelling choices can successfully address composite, more realistic research questions.

The association between resilience resources, contextual factors and mental health status: a national population-based study

Background

Although a range of risk factors have been linked with poor mental health across the population, the underlying pathways leading to mental ill health remain unclear. There is a need to investigate the effects and interplay of both protective and risk factors. This population-based study aimed to explore the effects of individual and contextual factors on mental health status. Record-linkage was implemented between health and lifestyle data drawn from HealthWise Wales (HWW), a national population health survey of people > 16 years who live or access their healthcare in Wales, and treatment data from primary healthcare records. Mental health status was assessed using three different measures, including the self-reported MHI-5 and WEMWBS scales and mental health treatment in electronic healthcare records (EHR).

Result

Using cross-sectional data from 27,869 HWW participants aged over 16 years, lifestyle factors, resilience, social cohesion and neighbourhood attraction were associated with mental health across all measures. However, compared to contextual factors, the cluster of individual factors was more closely associated with poor mental health, explaining more of the variance across all measures used (MHI-5: 9.8% versus 5.4%; WEMWBS: 15.9% versus 10.3%; EHR: 5.5% versus 3.0%). Additional analysis on resilience sub-constructs indicated that personal skills were the most closely correlated with poorer mental health.

Conclusion

Mental health status was more closely linked with individual factors across the population than contextual factors. Interventions focusing on improving individual resilience and coping skills could improve mental health outcomes and reduce the negative effect of contextual factors such as negative neighbourhood perceptions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13013-2.

The familial and genetic contribution to the association between depression and cardiovascular disease: a twin cohort study

Depression and cardiovascular disease (ischemic heart disease and stroke) are associated in a bidirectional manner. Their relatively high heritability has led to the hypothesis that this co-occurrence is related to shared familial and genetic factors; this study aims to test this hypothesis. We included 23,498 monozygotic and 39,540 same-sex dizygotic twins from the Danish Twin Registry followed from January 1977 until December 2011 in nationwide Danish registries. We used survival analyses accounting for censoring and competing risk of death to estimate cumulative incidence, casewise concordance, relative recurrence risk, and heritability of the co-occurrence of depression and cardiovascular disease by age using monozygotic and same-sex dizygotic twin pairs. The casewise concordance of ischemic heart disease or stroke in twins whose co-twin was diagnosed with depression was at all ages similar for the monozygotic and dizygotic twin pairs and to the cumulative incidence of ischemic heart disease or stroke, respectively, in the entire twin population. A similar pattern was seen in analyses of depression risk given the co-twin being diagnosed with ischemic heart disease or stroke. Relative recurrence risk and heritability estimates were also of modest size and with confidence intervals including unity. Results were similar after stratification by gender as well as when redefining depression to include the use of antidepressant medication from 1995. Our findings do not support that co-occurrence between depression and cardiovascular disease is explainable by shared genetic factors, nor did we find strong evidence of a familial effect.

Maternal depression and non-specific health complaints in the offspring: a cross-sectional study in Danish primary care

Background

Maternal depression has been linked to adverse outcomes in the offspring. Existing literature is mainly based on parental reports, which can be an unreliable source when the parent has depression.

Aim

To explore if maternal depression was associated with daily health complaints and low self-assessed health (SAH) in the offspring.

Design and setting

Participants were 45 727 children from the Danish National Birth Cohort recruited between 1996 and 2002. At 11-year follow-up, mothers and their children were invited to complete a questionnaire. Maternal depression was categorised into: no depression, first-time treatment, continued treatment, post-treatment, and relapse.

Method

Binomial regression was used to estimate the adjusted prevalence proportion ratio (aPPR) of frequent health complaints and low SAH in children of mothers with depression compared to children of mothers without depression.

Results

The prevalence of any daily health complaint was 11.4%, daily somatic complaints 4.1%, daily mental complaints 8.9%, both daily mental and somatic complaints 1.5%, and low SAH 5.3%. Children of mothers with depression (any category) were more likely to report a daily health complaint: first-time treatment aPPR 1.35 (95% confidence interval [CI] = 0.96 to 1.85), continued treatment aPPR 1.59 (95% CI = 1.37 to 1.85), post-treatment aPPR 1.30 (95% CI = 1.20 to 1.41), and relapse aPPR 1.56 (95% CI = 1.35 to 1.79). Children of mothers with depression were also more likely to report low SAH: first-time treatment aPPR 1.58 (95% CI = 0.99 to 2.54), continued treatment aPPR 1.86 (95% CI = 1.51 to 2.28), post-treatment aPPR 1.34 (95% CI = 1.19 to 1.50), and relapse aPPR 1.56 (95% CI = 1.26 to 1.93). Girls had a higher prevalence of mental and somatic health complaints and more often reported low SAH compared to boys.

Conclusion

Treatment of maternal depression was associated with higher prevalence of daily health complaints and low SAH in the offspring at age 11 years. The association was strongest for children of mothers with continued depression or relapse.

Identifying patients using antidepressants for the treatment of depression: A predictive algorithm for use in pharmaceutical and medical claims data

PURPOSE

Records of antidepressant dispensings are often used as a surrogate measure of depression. However, as antidepressants are frequently prescribed for indications other than depression, this is likely to result in misclassification. This study aimed to develop a predictive algorithm that identifies patients using antidepressants for the treatment of depression.

METHODS

Pharmaceutical Benefits Scheme (PBS) and Medicare Benefits Schedule (MBS) claims data were linked to follow-up questionnaires (completed in 2012-2013) for participants of the 45 and Up Study-a cohort study of residents of New South Wales, Australia, aged 45 years and older. The sample composed participants who were dispensed an antidepressant in the 30 days prior to questionnaire completion (n = 3162). An algorithm based on patient characteristics, pharmaceutical dispensings, and claims for mental health services was built using group-lasso interaction network (glinternet), with self-reported receipt of treatment for depression as the outcome. The predictive performance of the algorithm was assessed via bootstrap resampling.

RESULTS

The algorithm composes 15 main effects and 11 interactions, with type of antidepressant dispensed and claims for mental health services the strongest predictors. The ability of the algorithm to discriminate between antidepressant users with and without depression was 0.73. At a predicted probability cut-off of 0.6, specificity was 93.8% and sensitivity was 23.6%.

CONCLUSIONS

Using this algorithm with a high probability cut-off yields high specificity and facilitates the exclusion of individuals using antidepressants for indications other than depression, thereby mitigating the risk of confounding by indication when evaluating the outcomes of antidepressant use.

Consanguineous Marriage and the Psychopathology of Progeny: A Population-wide Data Linkage Study

IMPORTANCE

Approximately 1 in 10 children worldwide are born to consanguineous parents. The literature on consanguinity and mental health of progeny is scarce despite the fact that many of the factors associated with consanguineous unions are also associated with mental health.

OBJECTIVE

To investigate if children of consanguineous parents are at increased risk of common mood disorders or psychoses.

DESIGN, SETTING, AND PARTICIPANTS

This investigation was a retrospective population-wide cohort study of all individuals born in Northern Ireland between January 1, 1971, and December 31, 1986, derived from the Child Health System data set and linked to nationwide administrative data sources on prescription medication and death records. Data from the Child Health System data set identified all 447 452 births delivered to mothers residing in Northern Ireland between 1971 and 1986. The final data set comprised 363 960 individuals, alive and residing in Northern Ireland in 2014, with full data on all variables. The dates of analysis were June 1 to October 31, 2017.

MAIN OUTCOMES AND MEASURES

Degree of parental consanguinity was assessed from questions asked of the parents during routine health visitor house calls within 2 weeks of the child's birth. Potential mental ill health was estimated by receipt of psychotropic medication in 2010 to 2014. Ever or never use was used for the main analysis, with sensitivity analyses using a cutoff of at least 3 months' prescriptions. Receipt of antidepressant or anxiolytic medications was used as a proxy for common mood disorders, whereas receipt of antipsychotic medications was used as a proxy indicator of psychoses.

RESULTS

Of the 363 960 individuals (52.5% [191 102] male), 609 (0.2%) were born to consanguineous parents. After full adjustment for factors known to be associated with poor mental health, multilevel logistic regression models found that children of first-cousin consanguineous parents were more than 3 times as likely to be in receipt of antidepressant or anxiolytic medications (odds ratio, 3.01; 95% CI, 1.24-7.31) and more than twice as likely to be in receipt of antipsychotic medication (odds ratio, 2.13; 95% CI, 1.29-3.51) compared with children of nonrelated parents.

CONCLUSIONS AND RELEVANCE

A child of consanguineous parents is at increased risk of common mood disorders and psychoses.

Derivation and validation of a multivariable model to predict when primary care physicians prescribe antidepressants for indications other than depression

Objective

Physicians commonly prescribe antidepressants for indications other than depression that are not evidence-based and need further evaluation. However, lack of routinely documented treatment indications for medications in administrative and medical databases creates a major barrier to evaluating antidepressant use for indications besides depression. Thus, the aim of this study was to derive a model to predict when primary care physicians prescribe antidepressants for indications other than depression and to identify important determinants of this prescribing practice.

Methods

Prediction study using antidepressant prescriptions from January 2003–December 2012 in an indication-based electronic prescribing system in Quebec, Canada. Patients were linked to demographic files, medical billings data, and hospital discharge summary data to create over 370 candidate predictors. The final prediction model was derived on a random 75% sample of the data using 3-fold cross-validation integrated within a score-based forward stepwise selection procedure. The performance of the final model was assessed in the remaining 25% of the data.

Results

Among 73,576 antidepressant prescriptions, 32,405 (44.0%) were written for indications other than depression. Among 40 predictors in the final model, the most important covariates included the molecule name, the patient’s education level, the physician’s workload, the prescribed dose, and diagnostic codes for plausible indications recorded in the past year. The final model had good discrimination (concordance (c) statistic 0.815; 95% CI, 0.787–0.847) and good calibration (ratio of observed to expected events 0.986; 95% CI, 0.842–1.136).

Conclusion

In the absence of documented treatment indications, researchers may be able to use health services data to accurately predict when primary care physicians prescribe antidepressants for indications other than depression. Our prediction model represents a valuable tool for enabling researchers to differentiate between antidepressant use for depression versus other indications, thus addressing a major barrier to performing pharmacovigilance research on antidepressants.

Screening for psychiatric morbidity in the population - a comparison of the GHQ-12 and self-reported medication use

Introduction

Uptake of psychotropic medication has been previously used as a proxy for assessing the prevalence of population mental health morbidity. However, it is not known how this compares with estimates derived from population screening tools.

Objective

To compare estimates of psychiatric morbidity derived by a validated screening instrument of psychiatric morbidity and a self-reported medication uptake measure.

Methods

This study used data from two recent population-wide health surveys in Northern Ireland, a country (UK) with free health services and no prescription charges. The psychiatric morbidity of 7,489 respondents was assessed using the GHQ-12 and self-reported use of medication for stress, anxiety and depression (sDAS medication).

Results

Overall, 19% of respondents were defined as ‘cases’ and 14.3% were taking sDAS medication. Generally, the two methods identified the same population distributions of characteristics that were associated with psychiatric morbidity though nearly as many non-cases as cases received sDAS medication (46.4% vs. 53.6%). A greater proportion of women and older people were identified as cases according to sDAS medication use, while no such variation was observed between socio-economic status and method of assessment.

Conclusions

This study indicates that these two methods of assessing population psychiatric morbidity provide similar estimates, despite potentially identifying different individuals as cases. It is important to note that different health care systems might be linked to variations in obstacles when accessing and using health care services.

Highlights

Simultaneous Antidepressant and Benzodiazepine New Use and Subsequent Long-term Benzodiazepine Use in Adults With Depression, United States, 2001-2014

IMPORTANCE

Benzodiazepines have been prescribed for short periods to patients with depression who are beginning antidepressant therapy to improve depressive symptoms more quickly, mitigate concomitant anxiety, and improve antidepressant treatment continuation. However, benzodiazepine therapy is associated with risks, including dependency, which may take only a few weeks to develop.

OBJECTIVES

To examine trends in simultaneous benzodiazepine and antidepressant new use among adults with depression initiating an antidepressant, assess antidepressant treatment length by simultaneous new use status, estimate subsequent long-term benzodiazepine use in those with simultaneous antidepressant and benzodiazepine new use, and identify determinants of simultaneous new use and long-term benzodiazepine use.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study using a US commercial claims database included commercially insured adults (aged 18-64 years) from January 1, 2001, through December 31, 2014, with a recent depression diagnosis who began antidepressant therapy but had not used antidepressants or benzodiazepines in the prior year.

EXPOSURES

Simultaneous new use, defined as a new benzodiazepine prescription dispensed on the same day as a new antidepressant prescription.

MAIN OUTCOMES AND MEASURES

The proportion of antidepressant initiators with simultaneous new use and continuing antidepressant treatment for 6 months and the proportion of simultaneous new users receiving long-term (6-months) benzodiazepine therapy.

RESULTS

Of the 765 130 adults (median age, 39 years; interquartile range, 29-49 years; 507 451 women [66.3%]) who initiated antidepressant treatment, 81 020 (10.6%) also initiated benzodiazepine treatment. The mean annual increase in the proportion simultaneously starting use of both agents from 2001 to 2014 was 0.49% (95% CI, 0.47%-0.51%), increasing from 6.1% (95% CI, 5.5%-6.6%) in 2001 to 12.5% (95% CI, 12.3%-12.7%) in 2012 and stabilizing through 2014 (11.3%; 95% CI, 11.1%-11.5%). Similar findings were apparent by age group and physician type. Antidepressant treatment length was similar in simultaneous new users and non-simultaneous new users. Among simultaneous new users, 12.3% (95% CI, 12.0%-12.5%) exhibited long-term benzodiazepine use (64.0% discontinued taking benzodiazepines after the initial fill). Determinants of long-term benzodiazepine use after simultaneous new use were longer initial benzodiazepine days' supply, first prescription for a long-acting benzodiazepine, and recent prescription opioid fills.

CONCLUSIONS AND RELEVANCE

One-tenth of antidepressant initiators with depression simultaneously initiated benzodiazepine therapy. No meaningful difference in antidepressant treatment at 6 months was observed by simultaneous new use status. Because of the risks associated with benzodiazepines, simultaneous new use at antidepressant initiation and the benzodiazepine regimen itself require careful consideration.

Can Electronic Health Records Be Used for Population Health Surveillance? Validating Population Health Metrics Against Established Survey Data

INTRODUCTION

Electronic health records (EHRs) offer potential for population health surveillance but EHR-based surveillance measures require validation prior to use. We assessed the validity of obesity, smoking, depression, and influenza vaccination indicators from a new EHR surveillance system, the New York City (NYC) Macroscope. This report is the second in a 3-part series describing the development and validation of the NYC Macroscope. The first report describes in detail the infrastructure underlying the NYC Macroscope; design decisions that were made to maximize data quality; characteristics of the population sampled; completeness of data collected; and lessons learned from doing this work. This second report, which addresses concerns related to sampling bias and data quality, describes the methods used to evaluate the validity and robustness of NYC Macroscope prevalence estimates; presents validation results for estimates of obesity, smoking, depression and influenza vaccination; and discusses the implications of our findings for NYC and for other jurisdictions embarking on similar work. The third report applies the same validation methods described in this report to metabolic outcomes, including the prevalence, treatment and control of diabetes, hypertension and hyperlipidemia.

METHODS

NYC Macroscope prevalence estimates, overall and stratified by sex and age group, were compared to reference survey estimates for adult New Yorkers who reported visiting a doctor in the past year. Agreement was evaluated against 5 a priori criteria. Sensitivity and specificity were assessed by examining individual EHR records in a subsample of 48 survey participants.

RESULTS

Among adult New Yorkers in care, the NYC Macroscope prevalence estimate for smoking (15.2%) fell between estimates from NYC HANES (17.7 %) and CHS (14.9%) and met all 5 a priori criteria. The NYC Macroscope obesity prevalence estimate (27.8%) also fell between the NYC HANES (31.3%) and CHS (24.7%) estimates, but met only 3 a priori criteria. Sensitivity and specificity exceeded 0.90 for both the smoking and obesity indicators. The NYC Macroscope estimates of depression and influenza vaccination prevalence were more than 10 percentage points lower than the estimates from either reference survey. While specificity was > 0.90 for both of these indicators, sensitivity was < 0.70.

DISCUSSION

Through this work we have demonstrated that EHR data from a convenience sample of providers can produce acceptable estimates of smoking and obesity prevalence among adult New Yorkers in care; gained a better understanding of the challenges involved in estimating depression prevalence from EHRs; and identified areas for additional research regarding estimation of influenza vaccination prevalence. We have also shared lessons learned about how EHR indicators should be constructed and offer methodologic suggestions for validating them.

CONCLUSIONS

This work adds to a rapidly emerging body of literature about how to define, collect and interpret EHR-based surveillance measures and may help guide other jurisdictions.

Education as a predictor of antidepressant and anxiolytic medication use after bereavement: a population-based record linkage study

Purpose

Educational attainment has been shown to be positively associated with mental health and a potential buffer to stressful events. One stressful life event likely to affect everyone in their lifetime is bereavement. This paper assesses the effect of educational attainment on mental health post-bereavement.

Methods

By utilising large administrative datasets, linking Census returns to death records and prescribed medication data, we analysed the bereavement exposure of 208,332 individuals aged 25–74 years. Two-level multi-level logistic regression models were constructed to determine the likelihood of antidepressant medication use (a proxy of mental ill health) post-bereavement given level of educational attainment.

Results

Individuals who are bereaved have greater antidepressant use than those who are not bereaved, with over a quarter (26.5 %) of those bereaved by suicide in receipt of antidepressant medication compared to just 12.4 % of those not bereaved. Within individuals bereaved by a sudden death, those with a university degree or higher qualifications are 73 % less likely to be in receipt of antidepressant medication compared to those with no qualifications, after full adjustment for demographic, socio-economic and area factors (OR 0.27, 95 % CI 0.09,0.75). Higher educational attainment and no qualifications have an equivalent effect for those bereaved by suicide.

Conclusions

Education may protect against poor mental health, as measured by the use of antidepressant medication, post-bereavement, except in those bereaved by suicide. This is likely due to the improved cognitive, personal and psychological skills gained from time spent in education.

Electronic supplementary material

The online version of this article (doi:10.1007/s11136-016-1440-1) contains supplementary material, which is available to authorized users.

Prescription patterns of antiepileptic drugs in young women: development of a tool to distinguish between epilepsy and psychiatric disorders

BACKGROUND

Antiepileptic drugs (AEDs) are also prescribed for therapeutic indications other than epilepsy (EPI), namely, psychiatric disorders (PSY). Our aim was to develop an algorithm able to distinguish between EPI and PSY among childbearing age women based on differences in AED exposure in these patient groups.

METHODS

Two groups of women (18-45 years) with EPI or PSY treated with AEDs in the first semester of 2010 or 2011 were extracted from paper or electronic medical charts of specialized centers. Through the prescription database of Bologna Local Health Authority (Italy), AEDs, treatment schedule and co-treatments were collected for each patient. A prescription-based hierarchical classification system was developed. The algorithm obtained was subsequently validated on internal and external data.

RESULTS

Eighty-one EPI and 94 PSY subjects were recruited. AED monotherapy was the most common choice in both groups (69% EPI vs 79% PSY). Some AEDs were used only in EPI, others exclusively in PSY. Co-treatments with antipsychotics (6% vs 67%), lithium (0% vs 9%), and antidepressants (7% vs 70%) were fewer in EPI than in PSY. The hierarchical classification system identified antipsychotics, SSRIs (Selective Serotonin Reuptake Inhibitors), and number of AEDs as variables to discriminate EPI and PSY, with an overall error rate estimate of 9.7% (95%CI: 5.3% to 14.1%).

CONCLUSION

Among the differences between EPI and PSY, prescription data alone allowed an algorithm to be developed to diagnose each childbearing age woman receiving AEDs. This approach will be useful to stratify patients for risk estimates of AED-treated patients based on administrative databases. Copyright © 2016 John Wiley & Sons, Ltd.

Residential segregation, dividing walls and mental health: a population-based record linkage study

Background

Neighbourhood segregation has been described as a fundamental determinant of physical health, but literature on its effect on mental health is less clear. While most previous research has relied on conceptualised measures of segregation, Northern Ireland is unique as it contains physical manifestations of segregation in the form of segregation barriers (or ‘peacelines’) which can be used to accurately identify residential segregation.

Methods

We used population-wide health record data on over 1.3 million individuals, to analyse the effect of residential segregation, measured by both the formal Dissimilarity Index and by proximity to a segregation barrier, on the likelihood of poor mental health.

Results

Using multilevel logistic regression models, we found residential segregation measured by the Dissimilarity Index poses no additional risk to the likelihood of poor mental health after adjustment for area-level deprivation. However, residence in an area segregated by a ‘peaceline’ increases the likelihood of antidepressant medication by 19% (OR=1.19, 95% CI 1.14 to 1.23) and anxiolytic medication by 39% (OR=1.39, 95% CI 1.32 to 1.48), even after adjustment for gender, age, conurbation, deprivation and crime.

Conclusions

Living in an area segregated by a ‘peaceline’ is detrimental to mental health suggesting segregated areas characterised by a heightened sense of ‘other’ pose a greater risk to mental health. The difference in results based on segregation measure highlights the importance of choice of measure when studying segregation.

Depression After First Hospital Admission for Acute Coronary Syndrome: A Study of Time of Onset and Impact on Survival

We examined incidence of depression after acute coronary syndrome (ACS) and whether the timing of depression onset influenced survival. All first-time hospitalizations for ACS (n = 97,793) identified in the Danish Patient Registry during 2001-2009 and a reference population were followed for depression and mortality via linkage to patient, prescription, and cause-of-death registries until the end of 2012. Incidence of depression (as defined by hospital discharge or antidepressant medication use) and the relationship between depression and mortality were examined using time-to-event models. In total, 19,520 (20.0%) ACS patients experienced depression within 2 years after the event. The adjusted rate ratio for depression in ACS patients compared with the reference population was 1.28 (95% confidence interval (CI): 1.25, 1.30). During 12 years of follow-up, 39,523 (40.4%) ACS patients and 27,931 (28.6%) of the reference population died. ACS patients with recurrent (hazard ratio (HR) = 1.62, 95% CI: 1.57, 1.67) or new-onset (HR = 1.66, 95% CI: 1.60, 1.72) depression had higher mortality rates than patients with no depression. In the reference population, the corresponding relative estimates for recurrent (HR =1.98, 95% CI: 1.92, 2.05) and new-onset (HR = 2.42, 95% CI: 2.31, 2.54) depression were stronger. Depression is common in ACS patients and is associated with increased mortality independently of time of onset, but here the excess mortality associated with depression seemed to be lower in ACS patients than in the reference population.

Integrated Primary Care Teams (IPCT) pilot project in Quebec: a protocol paper

INTRODUCTION

The overall aim of this project is to help develop knowledge about primary care delivery models likely to improve the accessibility, quality and efficiency of care. Operationally, this objective will be achieved through supporting and evaluating 8 primary care team pilot sites that rely on an expanded nursing role within a more intensive team-based, interdisciplinary setting.

METHODS AND ANALYSIS

The first research component is aimed at supporting the development and implementation of the pilot projects, and is divided into 2 parts. The first part is a logical analysis based on interpreting available scientific data to understand the causal processes by which the objectives of the intervention being studied may be achieved. The second part is a developmental evaluation to support teams in the field in a participatory manner and thereby learn from experience. Operationally, the developmental evaluation phase mainly involves semistructured interviews. The second component of the project design focuses on evaluating pilot project results and assessing their costs. This component is in turn made up of 2 parts. Part 1 is a pre-and-post survey of patients receiving the intervention care to analyse their care experience. In part 2, each patient enrolled in part 1 (around 4000 patients) will be matched with 2 patients followed within a traditional primary care model, so that a comparative analysis of the accessibility, quality and efficiency of the intervention can be performed. The cohorts formed in this way will be followed longitudinally for 4 years.

ETHICS AND DISSEMINATION

The project, as well as all consent forms and research tools, have been accepted by 2 health sciences research ethics committees. The procedures used will conform to best practices regarding the anonymity of patients.

The Impact of Comorbid Depression on Educational Inequality in Survival after Acute Coronary Syndrome in a Cohort of 83 062 Patients and a Matched Reference Population

Background

Patients with low socioeconomic position have higher rates of mortality after diagnosis of acute coronary syndrome (ACS), but little is known about the mechanisms behind this social inequality. The aim of the present study was to examine whether any educational inequality in survival after ACS was influenced by comorbid conditions including depression.

Methods

From 2001 to 2009 all first-time ACS patients were identified in the Danish National Patient Registry. This cohort of 83 062 ACS patients and a matched reference population were followed for incident depression and mortality until December 2012 by linkage to person, patients and prescription registries. Educational status was defined at study entry and the impact of potential confounders and mediators (age, gender, cohabitation status, somatic comorbidity and depression) on the relation between education and mortality were identified by drawing a directed acyclic graph and analysed using multiple Cox regression analyses.

Findings

During follow-up, 29 583(35.6%) of ACS patients and 19 105(22.9%) of the reference population died. Cox regression analyses showed an increased mortality in the lowest educated compared to those with high education in both ACS patients and the reference population. Adjustment for previous and incident depression or other covariables only attenuated the relations slightly. This pattern of associations was seen for mortality after 30 days, 1 year and during total follow-up.

Conclusion

In this study the relative excess mortality rate in lower educated ACS patients was comparable with the excess risk associated with low education in the background population. This educational inequality in survival remained after adjustment for somatic comorbidity and depression.

Does conurbation affect the risk of poor mental health? A population based record linkage study

To determine if urban residence is associated with an increased risk of anxiety/depression independent of psychosocial stressors, concentrated disadvantage or selective migration between urban and rural areas, this population wide record-linkage study utilised data on receipt of prescription medication linked to area level indicators of conurbation and disadvantage. An urban/rural gradient in anxiolytic and antidepressant use was evident that was independent of variation in population composition. This gradient was most pronounced amongst disadvantaged areas. Migration into increasingly urban areas increased the likelihood of medication. These results suggest increasing conurbation is deleterious to mental health, especially amongst residents of deprived areas.

From patient care to research: a validation study examining the factors contributing to data quality in a primary care electronic medical record database

Background

Electronic Medical Records (EMRs) are increasingly used in the provision of primary care and have been compiled into databases which can be utilized for surveillance, research and informing practice. The primary purpose of these records is for the provision of individual patient care; validation and examination of underlying limitations is crucial for use for research and data quality improvement. This study examines and describes the validity of chronic disease case definition algorithms and factors affecting data quality in a primary care EMR database.

Methods

A retrospective chart audit of an age stratified random sample was used to validate and examine diagnostic algorithms applied to EMR data from the Manitoba Primary Care Research Network (MaPCReN), part of the Canadian Primary Care Sentinel Surveillance Network (CPCSSN). The presence of diabetes, hypertension, depression, osteoarthritis and chronic obstructive pulmonary disease (COPD) was determined by review of the medical record and compared to algorithm identified cases to identify discrepancies and describe the underlying contributing factors.

Results

The algorithm for diabetes had high sensitivity, specificity and positive predictive value (PPV) with all scores being over 90%. Specificities of the algorithms were greater than 90% for all conditions except for hypertension at 79.2%. The largest deficits in algorithm performance included poor PPV for COPD at 36.7% and limited sensitivity for COPD, depression and osteoarthritis at 72.0%, 73.3% and 63.2% respectively. Main sources of discrepancy included missing coding, alternative coding, inappropriate diagnosis detection based on medications used for alternate indications, inappropriate exclusion due to comorbidity and loss of data.

Conclusions

Comparison to medical chart review shows that at MaPCReN the CPCSSN case finding algorithms are valid with a few limitations. This study provides the basis for the validated data to be utilized for research and informs users of its limitations. Analysis of underlying discrepancies provides the ability to improve algorithm performance and facilitate improved data quality.

Antidepressant prescribing in five European countries: application of common definitions to assess the prevalence, clinical observations, and methodological implications

PURPOSE

Drug utilization studies have applied different methods to various data types to describe medication use, which hampers comparisons across populations. The aim of this study was to describe the time trends in antidepressant prescribing in the last decade and the variation in the prevalence, calculated in a uniform manner, in seven European electronic healthcare databases.

METHODS

Annual prevalence per 10,000 person-years (PYs) was calculated for 2001-2009 in databases from Spain, Germany, Denmark, the United Kingdom (UK), and the Netherlands. Prevalence data were stratified according to age, sex, antidepressant type (selective serotonin re-uptake inhibitors [SSRIs] or tricyclic antidepressants [TCAs]) and major indications.

RESULTS

The age- and sex-standardized prevalence was lowest in the two Dutch (391 and 429 users per 10,000 PYs) and highest in the two UK (913 and 936 users per 10,000 PYs) populations in 2008. The prevalence in the Danish, German, and Spanish populations was 637, 618, and 644 users per 10,000 PY respectively. Antidepressants were prescribed most often in 20- to 60-year-olds in the two UK populations compared with the others. SSRIs were prescribed more often than TCAs in all except the German population. In the majority of countries we observed an increasing trend of antidepressant prescribing over time. Two different methods identifying recorded indications yielded different ranges of proportions of patients recorded with the specific indication (15-57% and 39-69% for depression respectively).

CONCLUSION

Despite applying uniform methods, variations in the prevalence of antidepressant prescribing were obvious in the different populations. Database characteristics and clinical factors may both explain these variations.

Factors associated with switching and combination use of antidepressants in young Swedish adults

AIMS

Little is known on factors associated with switching and combination use of antidepressants. Our aim was to describe such use and to analyse the association with socioeconomic factors and level of care in Swedish adults aged 20-34 years.

METHODS

Individuals, aged 20-34 years, who purchased an antidepressant in January-June 2006, and who had not purchased any antidepressant in the preceding 6 months (n = 24,897) were followed from 6 up to 12 months. Among those who purchased ≥ 2 antidepressant substances, switchers were defined as those who did not fulfil the requirements for combination use. Data on purchased antidepressants and socioeconomic characteristics were obtained from the Swedish Prescribed Drug Register and Statistics Sweden. The association between (i) ≥ 2 antidepressants or (ii) switching, respectively, and socioeconomic factors as well as level of care was analysed with multiple logistic regression.

RESULTS

A total of 4254 individuals (17%) purchased ≥ 2 antidepressant substances, and the remaining 20,643 (83%) purchased one antidepressant. The adjusted odds ratio (OR) for purchase of ≥ 2 antidepressants (vs. purchase of one antidepressant only) was higher among those who started on mirtazapine compared with selective serotonin re-uptake inhibitors: 2.23 (95% confidence interval: 1.93-2.57), and lower in individuals with high education: 0.64 (0.54-0.75), and shorter length of follow-up: 0.73 (0.62-0.85). Among those with ≥ 2 antidepressants, 71.6% were classified as switchers. The adjusted OR for switching (vs. combination use) were higher among divorced/widows/widowers: 1.61 (1.05-2.49), and lower among individuals with short university education: 0.58 (0.43-0.78), those starting on mirtazapine: 0.78 (0.62-0.97), and when treatment was initiated in psychiatric care: 0.75 (0.63-0.88).

CONCLUSIONS

One of six new users purchased at least two antidepressants, the majority were classified as switchers. Purchase patterns were associated with socioeconomic characteristics, in particular level of education, type of first purchased antidepressant, and level of care initiating treatment.

Lack of significant interactions between clopidogrel and proton pump inhibitor therapy: meta-analysis of existing literature

BACKGROUND

Published data regarding the effect of concomitant clopidogrel and proton pump inhibitor (PPI) therapy on cardiovascular outcomes have been conflicting.

AIM

To perform an updated meta-analysis in order to determine changes in risk differences (RD) between primary and secondary outcome analyses.

METHODS

Primary analysis was based on definite vascular outcomes, including all cause mortality, cardiac death, myocardial infarction, and/or stroke. Secondary analysis also incorporated probable cardiac events, which included re-hospitalization for cardiac symptoms or revascularization procedures. RD were combined using a random-effects model.

RESULTS

We reviewed 1,204 publications of which 26 studies (16 published articles, 10 abstracts) met inclusion criteria. The meta-analysis of outcomes from the two randomized controlled trials did not show an increased risk (RD 0.0, 95% CI -0.01, 0.01) for adverse outcomes. The meta-analysis of primary outcomes showed a RD of 0.02 (95% CI 0.01, 0.03) for all studies. The meta-analysis for secondary outcomes yielded a RD of 0.02 (95% CI 0.01-0.04) based on 19 published papers and abstracts. When primary and secondary outcomes were combined, the meta-analysis for published papers yielded an overall RD of 0.05 (95% CI 0.03-0.06).

CONCLUSIONS

In patients using concomitant clopidogrel and PPI therapy, the risk of adverse cardiac outcomes was 0% based on data from well-controlled randomized trials. Data from retrospective studies and the addition of probable vascular events significantly increased the RD estimates, likely due to lack of adjustment for potential confounders.

Adherence to osteoporosis medications amongst Singaporean patients

Compliance and persistence to bisphosphonates amongst Singaporean patients with osteoporosis were estimated. Mean medication possession ratio (MPR) ± standard deviation (SD) was 78.9 ± 27.5%, and 69.0% was persistent at 1 year. In contrast to US and Europe where poor adherence is noted, our study suggests higher adherence rates to bisphosphonate therapy amongst patients.

INTRODUCTION

Adherence to bisphosphonate therapy during treatment of osteoporosis has been reported to be poor. We aimed to estimate the compliance and persistence to prescribed bisphosphonate therapy amongst patients at the largest public restructured hospital in Singapore.

METHODS

This is a retrospective analysis of records of patients who were prescribed the two most commonly used oral bisphosphonates-alendronate and risedronate. The study was conducted between January 2007 and December 2008. Prescription and pharmacy refill records of all patients were extracted and matched. Compliance was calculated using the MPR, while persistence, a dichotomous variable, was defined as continuous refill of bisphosphonates for at least 12 months with a permissible gap of 30 days.

RESULTS

Seven hundred ninety-eight patients were included in the study. Mean MPR ± SD was 78.9 ± 27.5%, and 69.0% of the patients were persistent with bisphosphonate therapy at 1 year. The proportion of patients with MPR ≥ 80% at 6, 12 and 18 months was 90%, 72% and 62%, respectively. Age <69 years was associated with better compliance (OR, 1.34; 95% CI, 0.99-1.82; P = 0.043), and history of fractures was associated with better compliance (OR, 1.38; 95% CI, 1.02-1.87; P = 0.038) and persistence (OR, 1.33; 95% CI, 0.97-1.82; P = 0.046).

CONCLUSION

In contrast to studies conducted in the US and Europe that show poor adherence, our study suggests higher adherence rates to bisphosphonate therapy amongst Singaporean patients.

Antidepressants utilization among elderly in Lombardy from 2000 to 2007: dispensing trends and appropriateness

PURPOSE

To investigate the prevalence and incidence of antidepressant (AD) use in the elderly during an 8-year period and to evaluate AD treatment appropriateness.

METHODS

A population-based dispensation study on community-dwelling elderly of a large area in Lombardy was performed. Data were drawn from the regional administrative database and from a general practice registry. For each year, prevalence of AD use (i.e., at least one recorded dispensation) and AD treatment (i.e., at least four recorded dispensations) was compared.

RESULTS

The prevalence of AD use and treatment doubled and tripled, respectively. The greatest shift occurred between 2000 and 2002 and was entirely due to SSRIs. The most pronounced increase was seen in females who accounted for 72% of all dispensations. The increase in prevalence was not mirrored by incident use, which slightly decreased (OR: 0.98; 95% CI: 0.98-0.98). The proportion of those who received a minimally adequate AD treatment grew over the years (OR: 1.63; 95% CI: 1.59-1.68). The increase in prevalence of AD treatment was most pronounced among older age groups (ORs between 1.02 and 1.06 for age classes ≥75 years relative to the 65-69 age class; P < 0.001) and was proportional to that of depressive disorders.

CONCLUSIONS

A dramatic rise in dispensations was observed. The increasing prevalence of minimally adequately treated subjects and a possible decrease in untreated depression may reflect an improvement in the pharmacological treatment of depression. The increase in prevalence and not in the incidence of dispensations could be related to an inappropriate prolongation of treatment duration.

Comparison of the consumption of antidepressants in the immigrant and native populations in a Spanish health region: an observational study

Background

Health professionals and organizations in developed countries adapt slowly to the increase of ethnically diverse populations attending health care centres. Several studies report that attention to immigrant mental health comes up with barriers in access, diagnosis and therapeutics, threatening equity. This study analyzes differences in exposure to antidepressant drugs between the immigrant and the native population of a Spanish health region.

Methods

Cross-sectional study of the dispensation of antidepressant drugs to the population aged 15 years or older attending the public primary health centres of a health region, 232,717 autochthonous and 33,361 immigrants, during 2008. Data were obtained from computerized medical records and pharmaceutical records of medications dispensed in pharmacies. Age, sex, country of origin, visits, date of entry in the regional health system, generic drugs and active ingredients were considered. Statistical analysis expressed the percentage of persons exposed to antidepressants stratified by age, gender, and country of origin and prevalence ratios of antidepressant exposition were calculated.

Results

Antidepressants were dispensed to 11% of native population and 2.6% of immigrants. Depending on age, native women were prescribed antidepressants between 1.9 and 2.7 times more than immigrant women, and native men 2.5 and 3.1 times more than their immigrant counterparts. Among immigrant females, the highest rate was found in the Latin Americans (6.6%) and the lowest in the sub-Saharans (1.4%). Among males, the highest use was also found in the Latin Americans (1.6%) and the lowest in the sub-Saharans (0.7%). The percentage of immigrants prescribed antidepressants increased significantly in relation to the number of years registered with the local health system. Significant differences were found for the new antidepressants, prescribed 8% more in the native population than in immigrants, both in men and in women.

Conclusions

All the immigrants, regardless of the country of origin, had lower antidepressant consumption than the native population of the same age and sex. Latin American women presented the highest levels of consumption, and the sub-Saharan men the lowest. The prescription profiles also differed, since immigrants consumed more generics and fewer recently commercialized active ingredients.